The governmental structure of the City of Gautier is relatively young but the area has deep connections to the history of the gulf coast region. The City Manager-Council organizational structure has governed since 1987. Although the 2005 natural disaster slowed growth momentarily, the population of Gautier is expected to grow at a steady rate during the coming decades. The socio-economic demographics of the city is similar to that of Jackson County in terms of income, age, gender and education, although Gautier has a higher rate of college-educated persons. The income and employment of residents benefits greatly from the proximity of strong employment centers in Jackson County.

Gautier is located at 30°22′54″N 88°38′39″W / 30.38167°N 88.64417°W / 30.38167; -88.64417 (30.381536, -88.644169), along Mississippi Sound of the Gulf of Mexico, at the mouth of the West Pascagoula River.

According to the United States Census Bureau, the city has a total area of 12.9 square miles (33.5 km²), of which, 12.2 square miles (31.7 km²) of it is land and 0.7 square miles (1.7 km²) of it (5.19%) is water.

Gautier is located on the Mississippi Gulf Coast in Jackson County on the West Bank of the Pascagoula River, locally known as the "Singing River."

As of the census of 2000, there were 11,681 people, 4,260 households, and 3,233 families residing in the city. The population density was 954.2 people per square mile (368.5/km²). There were 4,597 housing units at an average density of 375.5/sq mi (145.0/km²). The racial makeup of the city was 68.19% White, 27.65% African American, 0.51% Native American, 1.28% Asian, 0.04% Pacific Islander, 0.90% from other races, and 1.42% from two or more races. Hispanic or Latino of any race were 3.19% of the population.

There were 4,260 households out of which 38.1% had children under the age of 18 living with them, 54.9% were married couples living together, 17.1% had a female householder with no husband present, and 24.1% were non-families. 19.3% of all households were made up of individuals and 4.5% had someone living alone who was 65 years of age or older. The average household size was 2.73 and the average family size was 3.11.

In the city the population was spread out with 28.4% under the age of 18, 9.8% from 18 to 24, 30.2% from 25 to 44, 23.3% from 45 to 64, and 8.3% who were 65 years of age or older. The median age was 33 years. For every 100 females there were 97.9 males. For every 100 females age 18 and over, there were 94.9 males.

The median income for a household in the city was $41,244, and the median income for a family was $46,835. Males had a median income of $33,474 versus $21,622 for females. The per capita income for the city was $17,525. About 15.1% of families and 17.3% of the population were below the poverty line, including 28.4% of those under age 18 and 13.6% of those age 65 or over.

The gracious homestead that Fernando Upton Gautier (1822–1891) established in 1867, at the mouth of the Pascagoula River Basin still stands, a hallmark of the city that now bears his name. Fernando Upton Gautier established a lucrative sawmill business in the area, and the town grew up from it. Today the town is known for its stately homes nestled between centuries-old Live Oaks and two championship golf courses. The home known by locals as "The Old Place" is still owned by the descendants of Theresa Fayard Gautier (1828–1911) and Fernando Upton Gautier and is currently being used for private and public events. Other historic homes of Gautier include that of Josie Gautier and the current Portas homestead, both Gulf Coastal cottage style homes from the 1890s.

The City of Gautier is served by the Pascagoula School District. The main secondary school in Gautier is Gautier High School.